UnityC＃　Fusion 別のプレイヤーの子オブジェクトになるには

実現したいこと

２番目に生成されるプレイヤーを
一番目に生成された別プレイヤーの子オブジェクトにする方法を教えてほしいです。

発生している問題・分からないこと

ゲームランチャーのコードで
①画面上にある「Finish」のタグのゲームオブジェクトを探して、GameObject 「G」にする
のところで
「Finish」タグが探すことができずにnullになってしまいます。

該当のソースコード

using Fusion;
using Fusion.Sockets;
using System.Collections.Generic;
using System;
using UnityEngine;

public class ゲームランチャー : MonoBehaviour, INetworkRunnerCallbacks
{
    public NetworkRunner networkRunnerPrefab;

public    NetworkPrefabRef playerAvatarPrefab;//タグ＝Finish



    public int spawnCount = 0;

   
    //public Transform potison1;


    // Start is called once before the first execution of Update after the MonoBehaviour is created

    private async void Start()
    {
        // NetworkRunnerを生成する
        var networkRunner = Instantiate(networkRunnerPrefab);

        // GameLauncherを、NetworkRunnerのコールバック対象に追加する
        networkRunner.AddCallbacks(this);
        networkRunner.AddCallbacks(FindObjectOfType<入力を集める>());
      
        // 共有モードのセッションに参加する
        var result = await networkRunner.StartGame(new StartGameArgs
        {
            GameMode = GameMode.Shared,
                
                
        });
        


        

    }

    // Update is called once per frame
    void INetworkRunnerCallbacks.OnObjectExitAOI(NetworkRunner runner, NetworkObject obj, PlayerRef player) { }
    void INetworkRunnerCallbacks.OnObjectEnterAOI(NetworkRunner runner, NetworkObject obj, PlayerRef player) { }
    void INetworkRunnerCallbacks.OnPlayerJoined(NetworkRunner runner, PlayerRef player)
    {



        spawnCount++;

        int currentIndex = spawnCount;
        if (player == runner.LocalPlayer)
        {


            //１番
            if (currentIndex == 1)
            {
              
                // 自分自身のアバターをスポーンする
                NetworkObject A = runner.Spawn(playerAvatarPrefab, transform.position, Quaternion.identity, player);


               
            }



            //２番
            if (currentIndex == 2)
            {

//「Finish」のタグのゲームオブジェクトを探す
                GameObject G = GameObject.FindWithTag("Finish");

                if (G == null)
                {
                    Debug.Log("NG");
                    return;
                }

                Debug.Log("Good!");

                // 自分自身のアバターをスポーンする
                NetworkObject A =  runner.Spawn(playerAvatarPrefab, new Vector3(0,1,0), Quaternion.identity, player);


　　　　　　//子オブジェクトにする
                G.transform.SetParent(A.transform, true);
            }
        }
    }

        void INetworkRunnerCallbacks.OnPlayerLeft(NetworkRunner runner, PlayerRef player) { }
    void INetworkRunnerCallbacks.OnInput(NetworkRunner runner, NetworkInput input) { }
    void INetworkRunnerCallbacks.OnInputMissing(NetworkRunner runner, PlayerRef player, NetworkInput input) { }
    void INetworkRunnerCallbacks.OnShutdown(NetworkRunner runner, ShutdownReason shutdownReason) { }
    void INetworkRunnerCallbacks.OnConnectedToServer(NetworkRunner runner) { }
    void INetworkRunnerCallbacks.OnDisconnectedFromServer(NetworkRunner runner, NetDisconnectReason reason) { }
    void INetworkRunnerCallbacks.OnConnectRequest(NetworkRunner runner, NetworkRunnerCallbackArgs.ConnectRequest request, byte[] token) { }
    void INetworkRunnerCallbacks.OnConnectFailed(NetworkRunner runner, NetAddress remoteAddress, NetConnectFailedReason reason) { }
    void INetworkRunnerCallbacks.OnUserSimulationMessage(NetworkRunner runner, SimulationMessagePtr message) { }
    void INetworkRunnerCallbacks.OnSessionListUpdated(NetworkRunner runner, List<SessionInfo> sessionList) { }
    void INetworkRunnerCallbacks.OnCustomAuthenticationResponse(NetworkRunner runner, Dictionary<string, object> data) { }
    void INetworkRunnerCallbacks.OnHostMigration(NetworkRunner runner, HostMigrationToken hostMigrationToken) { }

    public void OnReliableDataReceived(NetworkRunner runner, PlayerRef player, ReliableKey key, ReadOnlySpan<byte> data)
    {
    }

    public void OnReliableDataProgress(NetworkRunner runner, PlayerRef player, ReliableKey key, float progress)
    {
    }
    void INetworkRunnerCallbacks.OnSceneLoadDone(NetworkRunner runner) { }
    void INetworkRunnerCallbacks.OnSceneLoadStart(NetworkRunner runner) { }


}

using Fusion;
using UnityEngine;
using System;
using System.Collections.Generic;
using Fusion.Sockets;
public class 入力を集める : MonoBehaviour, INetworkRunnerCallbacks
{
    // Start is called once before the first execution of Update after the MonoBehaviour is created
   
    //入力データ型
    public struct MyInputData : INetworkInput
    {
        public NetworkBool up;
        public NetworkBool down;
        public NetworkBool left;
        public NetworkBool right;
    }


    //入力を集める側
    void INetworkRunnerCallbacks.OnInput(NetworkRunner runner, NetworkInput input) 
    {
        MyInputData data = new MyInputData();

        data.up = Input.GetKey(KeyCode.UpArrow);
        data.down = Input.GetKey(KeyCode.DownArrow);
        data.left = Input.GetKey(KeyCode.LeftArrow);
        data.right = Input.GetKey(KeyCode.RightArrow);
      
  

        input.Set(data);
    }
    public void OnPlayerJoined(NetworkRunner runner, PlayerRef player) { }
    void INetworkRunnerCallbacks.OnPlayerLeft(NetworkRunner runner, PlayerRef player) { }
    //void INetworkRunnerCallbacks.OnInput(NetworkRunner runner, NetworkInput input) { }
    void INetworkRunnerCallbacks.OnInputMissing(NetworkRunner runner, PlayerRef player, NetworkInput input) { }
    void INetworkRunnerCallbacks.OnShutdown(NetworkRunner runner, ShutdownReason shutdownReason) { }
    void INetworkRunnerCallbacks.OnConnectedToServer(NetworkRunner runner) { }
    void INetworkRunnerCallbacks.OnDisconnectedFromServer(NetworkRunner runner, NetDisconnectReason reason) { }
    void INetworkRunnerCallbacks.OnConnectRequest(NetworkRunner runner, NetworkRunnerCallbackArgs.ConnectRequest request, byte[] token) { }
    void INetworkRunnerCallbacks.OnConnectFailed(NetworkRunner runner, NetAddress remoteAddress, NetConnectFailedReason reason) { }
    void INetworkRunnerCallbacks.OnUserSimulationMessage(NetworkRunner runner, SimulationMessagePtr message) { }
    void INetworkRunnerCallbacks.OnSessionListUpdated(NetworkRunner runner, List<SessionInfo> sessionList) { }
    void INetworkRunnerCallbacks.OnCustomAuthenticationResponse(NetworkRunner runner, Dictionary<string, object> data) { }
    void INetworkRunnerCallbacks.OnHostMigration(NetworkRunner runner, HostMigrationToken hostMigrationToken) { }

    public void OnReliableDataReceived(NetworkRunner runner, PlayerRef player, ReliableKey key, ReadOnlySpan<byte> data)
    {
    }

    public void OnReliableDataProgress(NetworkRunner runner, PlayerRef player, ReliableKey key, float progress)
    {
    }
    void INetworkRunnerCallbacks.OnSceneLoadDone(NetworkRunner runner) { }
    void INetworkRunnerCallbacks.OnSceneLoadStart(NetworkRunner runner) { }
    public void OnObjectEnterAOI(NetworkRunner runner, NetworkObject obj, PlayerRef player) { }
    public void OnObjectExitAOI(NetworkRunner runner, NetworkObject obj, PlayerRef player) { }

}

using Fusion;
using UnityEngine;


public class 移動する : NetworkBehaviour
{
    // Start is called once before the first execution of Update after the MonoBehaviour is created
    void Start()
    {


    }


   

    public override void FixedUpdateNetwork()
    {
        if (GetInput(out 入力を集める.MyInputData data))

        {
            if (data.up)
            {
                Debug.Log("Upを受信");
                transform.position += transform.forward * 2f * Runner.DeltaTime;
            }

            if (data.down)
            {
                
                transform.position -= transform.forward * 2f * Runner.DeltaTime;
            }

            if (data.right)
            {

                transform.position += transform.right * 2f * Runner.DeltaTime;
            }

            if (data.left)
            {

                transform.position -= transform.right * 2f * Runner.DeltaTime;
            }
        }

        else
        {
            Debug.Log("入力取得失敗");
        }

    }
}